双螺杆挤压对小麦膳食纤维改性的研究

以小麦膳食纤维为原料,采用双螺杆挤压技术,研究挤压条件对小麦膳食纤维的改性效果。结果表明:挤压的最佳工艺条件为加水量15%,出料口温度140℃,螺杆转速100 r/min。在此条件下,样品的持水力和膨胀力分别为4.18 g/g、3.45 mL/g,与挤压前相比,分别提高0.7 g/g、1.25 mL/g。挤压后基本成分变化为:水分和可溶性膳食纤维含量升高,淀粉、蛋白质和不溶性膳食纤维含量有所降低,其它成分含量基本未发生变化。显微观察,处理后样品较处理前样品组织结构更加疏松,粒度更加均匀。

Modifying Wheat Dietary Fiber with Double-Screw Extrusion

Modification of wheat dietary fiber（WDF）was studied by using a double-screw extruder.Results indicate that the optimal extrusion condition are as follows： material moisture 15%,extrusion temperature 140 ℃,screw rotation speed 100 r/min.At the condition,the water holding capacity of the WDF is 4.18 g/g,the swelling capacity is 3.45 mL/g,compare to the WDF before extrusion,0.7 g/g and 1.25 mL/g increased separately.After extrusion,the content of water and soluble dietary fiber were higher;starch,the content of protein and insoluble dietary fiber were lower;and the content of other basic ingredients didn’t have much change.With microscopic observation,the extruded WDF was looser in weave construction,uniformer in size.